Induction relay



Dec. 1, 1931. R sMlTH 1,834,431

INDUCTION RELAY Filed: Nov l5 1929 Q) (a a E r J' L.

JIH'NVENTOR Carrem (In/is 7 ATTORNEY I RoyMSmz'fb m provide an induction relay of the current-re- Patentecl Dec. 1, 1931 ROY M,- SMITH, GE Home mmo'ron, NEW IJiiItsEY', AssIGNo-R 10 wn's'rmr 'otsn EL c'rmceMANUFAcTURmo COMPANY, A CORPORATION OF PENNSYLVANIA est mationhee'ittvember 1mm. seehjm. 466,81.

Myinvention relates to induction relays and particularly to means for modifying the relation of the phase dispiao'ed actuating fluxes of: current-responsiverelays! One object of my invention is to provide a device of the above-indicatedcharacter that shall provide relatively great phase displace ment of its"actuatingv fluxes=' 1 Another object of my invention is to: pro vide' aninductio'n' relay inwhioh the phase displacement of its actuating fiuxe'sand thereby its operating torque, is not redued tititshigh-currentoperating-values. I

,Another object of my invention is to provide at self eontaihed induetionrelay unit in which the phase-displacement ofits' actuat ing fluxes is increased. Without recourse to external apparatus; such as resistors.

V A further, object of my inventioh'is to pro vide a relay 0r equivalentstriicture that shall be:--simp1e and durable eonstruc'tion, econom-icel to manufactlire: and efie'ctive in its operation. I .In'induction releysoi the eurrenterespom sive type, it'has heretoforebeen lis'li-itl to em ploy a single: means, such as 9; closed-circuit coil or loop, on the main flux-poleipor'tion of the field-maignetoore to increase the range of movement of the min-attire over" which it-has torque effective to actuate contact members; I III-such a device, while the flux-phase displacement is improved it not the maximum toWh-i'ch a relay of comparable s izeis capable, as evideneed by a suggestion callingfor' the use of an external r sistor'ih shufitrehitiofi to the relay winding. 7

However, the latter device; in addition to the ext rnal resistor; "or separate" ep erates,

wlhoh destroys the identity of the'reley as e1 single self-'c'c'mt'aihed unit; hasthe 'further'dis advantage of1 0sse's eaused by the esi tor;

rent relay of the induction type as a compz'tet self-contained unit'gthd at the same time, to

tame adventt eot'the ability of the reiey t0 utih z'e its torqu'e' capabilities to suhsiantizih y a maximum in accordance with its size ah-d space-l-i-niitatiom without undue loss.

Accordingly, 1n practicing my invention, I

soonsivetvpein which a plurality of'relative:

lysmall'closed-cirouit coils 0r loops, of a type heretofore used singly; are so disposed as'te:

attaini-the aim and objects ofmy invention witheut'un'du'el loss and withoutth'e sacrifice ofthe identity of the device as ay-s elf-com tainedunit. i i Fighre 1; of the accompanying drawings, is ediagmmmatie view of a eurreherespon sive relay embodying my invention,

I Fig. 21s a perspective view (if the" field eppliettioh or useocf the invention." I

f Re-terring to Fig. 1, the device comprises; geherohofield-magnet core 2, en enhatufe 3; st main of primary energizing current winding 4, secondary coils 7 a closed-circuit coilof 100p element 9 ande closed-circuit coihdoop'orla'g element 10 The'c 1-"e member? shown more cleairly' Fig. 2 4s of a type commonly empioyedinwatthoui meters and consists of e steak of flat-plane hon ieminetions. It is in the one of frame 01* loop having a portion 11 exteh l tng entirety around its perimeterin,

the piano 0% thel-emirmtiohs, main inward= l-j pro iecting pole portion 1 2 c'ehtrst11 y dis posed between-side portions 14 which merge ititdlztterally-projecting side, pole portions 135 disposed spaced relatiofi tothe' side s' of the free eh-d at the poleportioh Hen-d oppositely-projecting portions 16 oi the petirnetra l portion 14 at one side of the "Iti s my aim to retain the identity of oathhouf meters, that is" moiiht'ed 61f a sprifi g constrained shaft and is adapted to actuate contact members. The shaft, the spring, or other biasing means, the contact members and other elements, being of usual and wellknown character, are omitted as not necessary to a full understanding of the invention.

The current winding l takes the place of the usual watthour-meter voltage winding on the main pole portion 12 and is energized from a desired current source, through leads 21 and terminals 22. I

Viewing the device as illustrated in. Fig. 1, if the closed-circuit elements 9 and 10 are both omitted, there are fluxes supplied by the coils 9 and 7 which are in sufficiently displaced phase relation to turn the armature disk 8, as in a watthour' meter. If not constrained,.tl1e disk rotates but, if constrained, as by aspring, the disk turns against the constraining force by any desired amount within limits. It is the latter effect which is utilized in relays to close and open contactmaking-and-breaking devices to protect a circuit against current overloads or-to actuate a switch or other device in response to any predetermined current value in the winding 4.

However, without the closed-circuit loop 9 or 10,,the phase displacement of the coacting fluxes from the coils 4 and 7, respectively, is relatively small and the operating range of the instrument on which an effective contact-closing torque is obtained is also small. a

It has been suggested, prior to my invention, to employ one or the other of the closedcurrent loops 9 and 10 in a position similar to that illustrated for each but, to the best of my knowledge, it has never before been suggested to employ both elements 9 and 10 at the same time or in the one structure or relay.

In Fig. 3 is illustrated, in polar co-ordinates, the total phase-displacement of the actuating fluxes as effected by the closed-circuit elements 9 and 10 severally and together.

- The curve marked Loop 9 represents the phase displacement caused between the cooperating fluxes by the loop 9 by the distance it is rotated from the reference vector in the clockwise direction about the base of this vector. By observing the projection of this curve on the base line marked Current units, it is seen that, for small current values, the phase-displacement between the fluxes increases rapidly for only a relatively short increase of current and thereafter approaches zero.

The curve marked Loop 10 represents a substantially constantly increasing displacement in the phase-relation of the fluxes but this displacement is limited in its total value by the size or physical character of the instrument. Irrespective of the latter factor, when both loops 9 and 10 are employed, as shown, the total flux phase displacement is as represented by the curve marked Loops 9 and 10, combining the displacements of the loops 9 and 10 severally in such manner as to obtain a very materially improved characteristic' for the instrument.

By this means, the torque of the armature is increased over a considerably greater range, in an extremely simple, expeditious and economical manner, without destroying the identity of the relay as a compact selfcontained unit, without the use of extraneous apparatus and without the losses caused by such apparatus.

As illustrated in Fig. 4, two relays 2a and 25, each of the construction above described, are associated with branch circuits 27 and 28, respectively, of a main circuit 29, the windings 7 being connected to current transformers 3O and31 and the windings 9 being connected to a current transformer The latter is associated with the grounded neutral lead 35 of a polyphase transformer 36 that is connected to the circuit 29.

The circuits are such that a ground in either of the circuits 27 or 28 will cause the corresponding relay to operate to trip a circuit interrupter (not shown) in the grounded circuit without interfering with the operation of the other circuit.

WVhile I have shown and described a particular form of my invention, changes may be effected therein without departing from the spirit, and scope thereof, as set forth in the appended claims.

I claim as my invention:

1. In an induction-type relay having a 1'0- tatable armature member, main and secondary poles cooperating therewith, an energizing winding on said main pole and a wind ing on said secondary poles inductively related tosaid energizing winding, means for lagging the total flux in said main pole including a plurality of short-circuited conductors cooperating with said main pole and main energizing winding.

2. In an induction instrument having a rotatable armature member, a field-magnet core having amain pole and secondary poles cooperatingwith opposite sides of said armature member, respectively, an energizing winding positioned on said main pole and a winding on said secondary poles inductively related to said energizing winding, means for effecting the maximum lag of the total flux in said main pole comprising aclosed conducting loop positioned on said main pole adjacent said armature member and a short circuited turn positioned on said main pole displaced from said closed conducting loop.

In testimony whereof, I have hereunto sub scribed my name this 8th day of November,

ROY M. SMITH. 

